Preparation and Performance of Anode-supported LaGaO_3-based Electrolyte Solid Oxide Fuel Cells with Sm-doped CeO_2 Buffer Layers

Anode-supported solid oxide fuel cells(SOFCs) composed of NiO-SDC(Sm0.2Ce0.8O1.9) composite an-ode,thin tri-layer electrolyte,and La0.6Sr0.4Co0.8Fe0.2O3(LSCF)-La0.9Sr0.1Ga0.8Mg0.2O3-δ(LSGM) composite cathode were fabricated.The thin 11 μm SDC/15 μm LSGM/13 μm SDC tri-layer electrolyte was prepared by centrifugal casting and co-firing technique.Cell tests in air as oxidant and humidified hydrogen as fuel show a maximum power density of 0.92 W /cm2 at 800℃.However,the open-circuit voltage(OCV) of these cells is 0.89 V which is lower than the Nernst potential.The above result is due to electronic conductivity in the LSGM layer,resulting from Ni impurities that entered during co-firing with the NiO-SDC anode.While the SDC buffer layers are introduced as buffer layers,impedance measurements indicate that both the ohmic resistance and the polarization resistance dominate the cell performance.